Breast Lift Surgery is Done for Drooping and Sagging Breasts. Pregnancies typically result in breast enlargement for lactation and can also get bigger with weight gain. Once this stimulation is over and weight lost, sagging can occur. Surgery does not prevent this sagging process. So the question becomes is the sagging bad enough before future pregnancies to warrant the risk of new sagging again? There is no correct answer to this, but repeat surgery is not always possible. Waiting until pregnancies are done is one option to consider.